Unit test review

Front

Does the equation 2NaCl + 1F2 -> 2NaF + 1Cl2 follow the law of conservation of mass? Justify.

Back

Yes

Front

In a chemical reaction, 300 grams of reactant A are combined with 100 grams of reactant B. Both A and B react to completion. How much will the product weigh?

Back

400

Front

Can mass be created or destroyed?

Back

No

Front

Does this equation follow the law of conservation of mass?

Back

Yes

Front

A closed system contains a reaction where 8 grams of hydrogen (H₂) react with 32 grams of oxygen (O₂) to produce water (H₂O).

1. Calculate the total mass of the reactants before the reaction occurs.
2. Calculate the total mass of the products after the reaction occurs.
3. Explain how your calculations support the law of conservation of mass.

Back

40 grams before, 40 after, follows law of conservation of mass

Front

Which of the following is an example of a physical change?
Options: Rust forming on iron , Ice melting into water, Baking a cake, Digestion of food

Back

Ice melting into water

Front

Which of the following indicates a chemical change has occurred?

• Change in state
• Change in shape
• Production of gas
• Mixing of two substances

Back

Production of gas

Front

Which process describes only a physical change?

Back

Water evaporating from sugar water

Front

What occurs during the digestion of food in your stomach?

Back

Chemical breakdown of enzymes

Front

What happens to the atoms in a chemical reaction?

Back

They are rearranged into new combinations.